Troubleshooting and Repair 6-17
CRT Interface Check
FDD Interface Check
Check CN2 and CRT
cable
Check L44, L47, L49,
L48, L50
(RGB, Hsync, Vsync)
Check VGA clock
14.318MHz and
32.768KHz
Check U17
Pin71, Pin 93
END
NO
YES
NO
YES
START
5
Check BIOS Setup
Menu
Enter Correct FDD
Type
Check if FDD is
properly formatted
Format Diskette or
Change Diskette
Check FDD Power
Check +5V
Check Motor of FDD
operation
Check U27 Pin 100
(Motor0#) signal
END
NO
YES
NO
NO
NO
YES
YES
Check Seek
operation
Check U27
Pin 10, 1, 2, 5, 6, 9
NO
Check Read or Write
operation
Check U27
Pin 7, 8, 12, 14
NO
YES
YES
YES